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How to Convert HEIC to AVIF on Mac

To convert iPhone HEIC photos to AVIF on macOS, use Kompressor or sips. AVIF gives you HEIC-like file sizes in a format that all browsers display.

A screenshot of Kompressor for macOS converting HEIC to AVIF

Steps

  1. Download Kompressor for Mac or get it on the Mac App Store
  2. Open the Kompressor app
  3. Drag and drop your HEIC image(s) into Kompressor
  4. Select AVIF as your output format
  5. Adjust compression settings as needed
  6. Click on the ▷ (play) button to convert your HEIC image(s) offline

Kompressor is free to try: you get 3 conversions, and each conversion can include as many images as you want.

Why convert HEIC to AVIF?

HEIC and AVIF are close relatives. Both use a modern video codec to compress photos, and both make much smaller files than JPEG. The difference is where they work: HEIC is an Apple format that Chrome and Firefox do not display, and AVIF is an open format that all current browsers display.

Convert to AVIF when your iPhone photos go on the web and you want the smallest files. If the photos stay in your Apple devices, keep them as HEIC: a conversion gives you no benefit and loses a little quality.

How much smaller is AVIF? Our test

We converted 32 iPhone photos (HEIC, most of them 12 megapixels, 56.5 MB in total) to AVIF at the default quality of 80%. The AVIF files had a total size of 42.0 MB, which is 26% smaller than the HEIC originals. The conversion of all 32 photos took 4.2 seconds.

Tested in November 2026 with the conversion engine of Kompressor on a MacBook Pro (M3 Max, 14 cores) with macOS 27. Your results depend on the images.

Other ways to convert HEIC to AVIF on Mac

Terminal (sips)

sips is part of macOS and converts a whole folder with one command:

mkdir converted
sips -s format avif -s formatOptions 80 *.heic --out converted

The file name pattern is case-sensitive. If the names of your files end in .HEIC, write *.HEIC.

The number after formatOptions is the quality from 0 to 100. AVIF output needs a recent macOS version. Run sips --formats and look for "Writable" in the avif row. There is no preview, so you must open the results to check them.

Finder Quick Action

The Convert Image Quick Action in Finder offers only JPEG, PNG and HEIF. It cannot write AVIF.

When Kompressor is the better tool

AVIF quality numbers do not match JPEG quality numbers, so it is hard to guess the correct setting. In Kompressor you see the result and its file size before you convert, and you can convert a folder of photos in one step.

Which quality setting to use

Kompressor shows quality as a bar with ten steps, from 10% to 100%. The default is 80%, and it is a good start for photos. Before you convert, open the compare view: drag the slider across the image to see the original next to the result, with the real output file size. Lower the quality until you see a difference, then go one step back.

Questions

Which browsers support AVIF?

Current versions of Chrome, Firefox, Safari and Edge display AVIF. Safari supports it from version 16.1 on Mac and from version 16 on iPhone.

Is AVIF better than WebP?

AVIF usually makes smaller files than WebP at the same visual quality. WebP encodes faster and works in older browsers. For photos on a modern website, AVIF is the better choice. See also how to convert HEIC to WebP.

Is AVIF slow to encode?

AVIF takes more time to encode than JPEG or WebP. This is normal for the format.

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